Fibrin-Genipin Hydrogel for Cartilage Tissue Engineering in Nasal Reconstruction.

OBJECTIVES: Nasal reconstruction is limited by the availability of autologous cartilage. The aim is to investigate an adhesive biomaterial for tissue engineering of nasal cartilage by evaluating mechanical properties of hydrogels made of fibrin crosslinked with genipin as compared to native tissue. METHODS: Hydrogels of fibrin, fibrin-genipin, and fibrin-genipin with extracellular matrix (ECM) particles were created and evaluated with mechanical testing to determine compression, tensile, and shear properties. Rabbit nasal septal cartilage was harvested and tested in these modalities for comparison. Transmission electron microscopy characterized hydrogel structure. RESULTS: Fibrin-genipin gels had higher compressive, tensile, and shear moduli compared to fibrin alone or fibrin-genipin with ECM. However, all hydrogel formulations had lower moduli than the rabbit nasal septal cartilage. Electron microscopy showed genipin crosslinking increased structural density of the hydrogel and that cartilage ECM created larger structural features with lower crosslinking density. CONCLUSION: The addition of genipin significantly improved mechanical properties of fibrin hydrogels by increasing the compressive, tensile, and shear moduli. The addition of cartilage ECM, which can add native structure and composition, resulted in decreased moduli values. Fibrin-genipin is a bioactive and biomechanically stable hydrogel that may offer promise as a scaffold for cartilage tissue engineering in nasal reconstruction, yet further augmentation is required to match material properties of native nasal cartilage.

Decellularization of Human Nasal Septal Cartilage for the Novel Filler Material of Vocal Fold Augmentation.

OBJECTIVES: The clinical application of allogenic and/or xenogenic cartilage for vocal fold augmentation requires to remove the antigenic cellular component. The objective of this study was to assess the effect of cartilage decellularization and determine the change in immunogenicity after detergent treatment in human nasal septal cartilage flakes made by the freezing and grinding method. METHODS: Human nasal septal cartilages were obtained from surgical cases. The harvested cartilages were treated by the freezing and grinding technique. The obtained cartilage flakes were treated with 1% Triton X-100 or 2% sodium dodecyl sulfate (SDS) for decellularization of the cartilage flakes. Hematoxylin and eosin stain (H&E stain), surface electric microscopy, immunohistochemical stain for major histocompatibility complex I and II, and ELISA for DNA contents were performed to assess the effect of cartilage decellularization after detergent treatment. RESULTS: A total of 10 nasal septal cartilages were obtained from surgical cases. After detergent treatment, the average size of the cartilage flakes was significantly decreased. With H&E staining, the cell nuclei of decellularized cartilage flakes were not observed. The expression of major histocompatibility complex (MHC)-I and II antigens was not identified in the decellularized cartilage flakes after treatment with detergent. DNA content was removed almost entirely from the decellularized cartilage flakes. CONCLUSION: Treatment with 2% SDS or 1% Triton X-100 for 1 hour appears to be a promising method for decellularization of human nasal septal cartilage for vocal fold augmentation.

Structural characteristics of septal cartilage and mucoperichondrium.

AIM: During nasal septum surgery, elevation of mucoperichondrium from the anterior nasal septum may be more difficult than from the medial and posterior septum. This study aimed to evaluate any histological structural differences between the anterior and posterior nasal septum cartilage, mucoperichondrium and intervening tissue. MATERIAL AND METHOD: Unilateral mucoperichondrial flap elevation without infiltration was performed, after nasal tip and dorsum decortication, in four patients undergoing open septorhinoplasty. Full-thickness samples, including cartilage and mucoperichondrium, were removed from the anterior and posterior nasal septum and examined under light and electron microscopy. RESULTS: Light microscopy showed no difference between anterior and posterior septum specimens regarding perichondrial thickness and subperichondrial cell density. Demarcation between cartilage and perichondrium and between perichondrium and lamina propria was more regular in the posterior versus the anterior septum. Electron microscopy showed no difference in chondroblast activity at the two sites. CONCLUSION: The observed tissue demarcation irregularities may explain the greater reported difficulty in elevating anterior versus posterior nasal septum mucoperichondrium. Immunohistochemical examination would further elucidate these interstructural connections.